private static bool IsEqual(ConstantExpression left, ConstantExpression right)
{
if (left.ConstantType != right.ConstantType)
{
return(false);
}
if (left.ConstantType == ConstantType.Boolean)
{
BooleanConstantExpression leftBoolean = (BooleanConstantExpression)left;
BooleanConstantExpression rightBoolean = (BooleanConstantExpression)right;
return(leftBoolean.Value == rightBoolean.Value);
}
else if (left.ConstantType == ConstantType.Integer)
{
IntegerConstantExpression leftInteger = (IntegerConstantExpression)left;
IntegerConstantExpression rightInteger = (IntegerConstantExpression)right;
return(leftInteger.Value == rightInteger.Value);
}
else if (left.ConstantType == ConstantType.String)
{
StringConstantExpression leftString = (StringConstantExpression)left;
StringConstantExpression rightString = (StringConstantExpression)right;
return(string.Equals(leftString.Value, rightString.Value, StringComparison.OrdinalIgnoreCase));
}
else
{
throw new EnableInfoException(string.Format(CultureInfo.InvariantCulture, "Comparing {0} constants is not supported.", left.ConstantType));
}
}
private BooleanConstantExpression VisitInFunction(ReadOnlyCollection <Expression> args)
{
if (args != null && args.Count >= 2)
{
// The EnableInfo documentation states that the 'in' function returns true
// if the first parameter is equal to at least one of the following parameters.
ConstantExpression first = Visit(args[0]) as ConstantExpression;
if (first != null)
{
if (first.ConstantType == ConstantType.String)
{
string firstParameter = ((StringConstantExpression)first).Value;
for (int i = 1; i < args.Count; i++)
{
StringConstantExpression parameter = Visit(args[i]) as StringConstantExpression;
if (parameter != null && string.Equals(firstParameter, parameter.Value, StringComparison.OrdinalIgnoreCase))
{
return(BooleanConstantExpression.True);
}
}
}
else if (first.ConstantType == ConstantType.Integer)
{
int firstParameter = ((IntegerConstantExpression)first).Value;
for (int i = 1; i < args.Count; i++)
{
IntegerConstantExpression parameter = Visit(args[i]) as IntegerConstantExpression;
if (parameter != null && firstParameter == parameter.Value)
{
return(BooleanConstantExpression.True);
}
}
}
else if (first.ConstantType == ConstantType.Boolean)
{
bool firstParameter = ((BooleanConstantExpression)first).Value;
for (int i = 1; i < args.Count; i++)
{
BooleanConstantExpression parameter = Visit(args[i]) as BooleanConstantExpression;
if (parameter != null && firstParameter == parameter.Value)
{
return(BooleanConstantExpression.True);
}
}
}
}
}
return(BooleanConstantExpression.False);
}
